Okay! I was able to get the web interface for UBoot connected again. Thank you! Having the cable connected before power on was the key – I guess I hadn’t done that before.
However, when I flashed the image, I got the same result: it seemed to flash, and then the router rebooted but froze on “Booting” with four little dots left on the loading bar.
I tried again, with the same image:
https://downloads.openwrt.org/snapshots/targets/ath79/nand/openwrt-ath79-nand-glinet_gl-e750-squashfs-factory.img
I verified the SHA-256, it matches the 7116…d8 as listed on the OpenWRT page. Through the UBoot web interface, I can start that flash. It seems to take it, the device reboots, and starts the “Booting” loading bar. That goes most of the way, but then hangs on the last four dots.
I’m using a GL-E750C6.
I re-flashed the image from the GL-Inet website:
‘firmware/e750/release/openwrt-e750-3.105.img’
That restored back to normal function. I could boot and use the normal web interface just fine.
Through the “upgrade” function on the normal web interface, I tried to install either of the other versions from the OpenWRT site but they came back as “incorrect firmware format.”
I appreciate all your help with this! What am I missing at this point?